In a circulation-type liquid ejecting devices, a liquid ejecting head ejects liquid that is supplied from a liquid storage tank and then circulated along a circulation path passing through the liquid ejecting head and the liquid storage tank. Multiple temperature sensors are provided along the circulation path, and the temperature of the circulating liquid in the circulation path is measured. In such devices, a circuit board in a liquid ejecting head can be connected to a control board by a connection via a flexible board. However, connections of a multi-terminal, narrow-pitch flexible boards are often poor due to improper fitting of a connector to the flexible board. That is, if the flexible board is typically fitted obliquely with respect to a connector and the position of a terminal or terminals can be shifted, and a short-circuiting can occur with an adjacent terminal. Thus, some terminals may not be connected as intended. As a result, the liquid ejecting head and the liquid ejecting device may not operate properly or may be electrically broken due to an inappropriate voltage applied to a control circuit of the liquid ejecting head. The liquid ejecting device may malfunction without being noticed.